Help with Replace All

I'm trying to understand this Replace All feature. Is it similar to Ctrl-H in Word? I tried to do one, and it's not working.

I did Replace All command, then typed in Speaker A: and checked the box for Format and then copied "Interviewer:" (in italics)

When I run it on a job it inserts the Interviewer Heading instead of replacing the Speaker A. Maybe I'm misunderstanding this command?